Fatal haemorrhagic enteritis associated with elevated loads of Strongyloides chapini in a Capybara

MAGNI C; EBERHARDT M A; MARINI R; COSTA S; BELOTTI M; PEZZONE N; MORENO P; CANAL A; BELDOMENICO P M

Puerto Iguazú

Congreso; 59° Reunión anual de Wildlife Disease Association (WDA); 2010

Each Strongyloides species is typically associated with a single host species. Capybaras are hosts to Strongyloides chapini. To date, parasitism by S. chapini has not been reported associated with disease. Here we report a fatal case of haemorrhagic enteritis that was preceded by elevated loads of this parasite. On 28 August 2009, 30 capybaras were transported from a commercial farm to an experimental station. On September 3th, one 6-month-old female showed signs of diarrhoea and died three days later. Its faecal egg counts on September 3rd revealed high Strongyloides levels, as compared to those of the other capybaras. A full necropsy was conducted and relevant samples were taken and analyzed by routine histopathology. The most significant lesions were found in the gastrointestinal tract. Macroscopic lesions included pre-pyloric ulcers, fibrinous exudate attached to the small intestine mucosa, and the content was bloody and liquid along the whole tract. Microscopically, there was fibrinous-haemorrhagic enteritis, with villi and Lieberkuhn gland´s cells loss. Lamina propria and submucosa were profusely infiltrated with leukocytes, including abundant eosinophils. Mesenteric lymph nodes were reactive, while other lymph nodes were depleted. The fasciculated zone of the adrenal gland was hyperthofic and with signs of degeneration. Large numbers of S. chapini were recovered from the large intestine, but they were absent in the small intestine and stomach, where they normally belong. Our findings suggest that the ultimate cause of the fatal enteritis might have originated from an immunosuppression due to stress, nonetheless, while not necessarily the proximate cause of death, S. chapini most likely was an important contributory factor.